I. Field of the Invention
This invention pertains to air filtering apparatus and, more particularly, to air filtering apparatus having impact cleaning mechanisms for cleaning an air filter.
II. Description of the Prior Art
In the prior art, air filtering apparatus comprising air filters housed in a dedicated cabinet are known for removing contaminants from air exhausted from a machine in an industrial setting. Referred to as cabinet collectors, such air filtering apparatus draw dirty air from a machine such as a saw, grinder, packing machine or other source of dirty air. The cabinet collectors are usually dedicated to a particular machine in a factory and prevent the circulation of the generated contaminant into ambient air. Air flow from the machine is created by a motor/blower assembly which is housed within the dedicated cabinet.
Prior art cabinet collectors contained a plurality of cloth bags as a filter medium which collected contaminant on the outside of the bag. After a period of usage, the exterior surface of the bag would become so loaded with the contaminant that air flow through the bag would be retarded and the cabinet collector could not adequately draw contaminated air from the machine. At this point in operation, the bags would be shaken and distorted through manual or automatic means, to dislodge the loaded contaminant. The dislodged contaminant would fall into a pan in the bottom of the cabinet collector. The pan would then be removed from the collector and its contents disposed of in any suitable manner.
Several problems are encountered in use of cabinet collectors of the prior art. First, the cloth bags used as the filter media in prior art cabinet collectors are expensive. Also, the bags are difficult to install. The difficulty in installation results in erroneous installation techniques making leaks common in prior art cabinet collectors. Finally, fibrous material, such as wood chips produced in a saw, would become lodged between the bags or lodged into the bag fiber and would not be discharged during the shaking and distorting cleaning operation described above.